The so-called “flip-chip bonding” in which an electrode of a semiconductor chip and an electrode on the signal reading substrate are faced to each other and electrically connected via a conductive bump (bump electrode) has a structure as shown in FIG. 7. This structure includes a signal reading substrate 101, a semiconductor chip 102, pixel electrodes 103, conductive bumps 104, and an insulating layer 105.
The signal reading substrate 101 is a signal reading substrate, such as, e.g., a CMOS integrated circuit, in which the pixel electrodes 103 are arranged in a two-dimensional matrix, for example. Note that in place of the semiconductor chip, a substrate typified by a counter substrate or the like may be used. The pixel electrodes 103 are formed on the signal reading substrate 101. The conductive bumps 104 are formed on the semiconductor chip 102 as counter pixel electrodes at positions facing the pixel electrodes 103.
The flip-chip bonding shown in FIG. 7 is used for a light detector or a radiation detector to detect light or radiation and extract a signal obtained by detection. As the flip-chip bonding, in addition to metal bonding using a solder bump, a gold bump, etc., adhesive bonding such as conductive resin bonding which is bonding using an organic material or anisotropic conductive member bonding can be exemplified. In addition to the flip-chip bonding, it can also be applied to cases where both substrates are used as bonding targets (see, for example, Patent Document 1).